UMIP 163 - Add MAGICETH, MAGICUSD, ETHMAGIC and USDMAGIC as supported price identifiers

The DVM should support price requests for MAGIC/ETH and MAGIC/USDC pairs.
The canonical identifier should be MAGICETH and MAGICUSDC.

Community Review Call outcome - 13th June

GO with conditions

  • implementation details added
  • Price feed configuration added

Community Review Call outcome - 20th June

GO with conditions

  • github comments addressed